Answer:
135 minutes
Step-by-step explanation:
Let
y -----> the number of pages to finish reading the book
x ----> the number of hours
we know that
The linear equation in slope intercept form is equal to
[tex]y=mx+b[/tex]
where
m is the unit rate or slope of the linear equation
b is the y-intercept or initial value
In this problem we have
Xanthia
[tex]m=100\ pages/hour[/tex]
[tex]b=225\ pages[/tex]
[tex]y=-100x+225[/tex] ----> the slope is negative because is a decreasing function
For y=0
substitute and solve for x
[tex]0=-100x+225[/tex]
[tex]100x=225[/tex]
[tex]x=2.25\ hours[/tex] ---> Xanthia's time to finish reading the book
Molly
[tex]m=50\ pages/hour[/tex]
[tex]b=225\ pages[/tex]
[tex]y=-50x+225[/tex] ----> the slope is negative because is a decreasing function
For y=0
[tex]0=-50x+225[/tex]
[tex]50x=225[/tex]
[tex]x=4.5\ hours[/tex] --- Molly's time to finish reading the book
To find out how many more minutes than Xanthia would it take for Molly to finish reading the book, subtract Xanthia's time from Molly's time
[tex]4.5\ h-2.25\ h=2.25\ h[/tex]
Convert to minutes
Multiply by 60
[tex]2.25\ h=2.25(60)=135\ minutes[/tex]
Answer:
135 mins
Step-by-step explanation:
Reading the book takes Xanthia
$\frac{225}{100}=2.25$ hours.
It takes Molly
$\frac{225}{50}=4.5$ hours.
The difference is $2.25$ hours, or $2.25(60)=\boxed{135}$ minutes.